Respiratory syncytial virus (RSV) is an RNA virus of the genus Pneumovirus containing two main antigenic glycoproteins, F and G (1). Additional structural proteins include a major nucleocapsid protein (N), a nucleocapsid phosphoprotein (P), a large nucleocapsid protein (L), an envelope matrix protein (M), and a glycoprotein (22,000 daltons) (138). A virally encoded protein of about 9,500 daltons and other small proteins are also known to be in infected cells (138). Infections with RSV are referable to all segments of the respiratory tract, and are usually associated with fever, cough, runny nose and fatigue. This virus is a major human pathogen and a leading cause of bronchiolitis and pneumonia in infants, children, adults and the elderly (1). A major difficulty in developing an effective RSV vaccine has been the fact that natural infection confers, at most, only temporary protection against the disease (1).
Prior to the present invention, only one RSV vaccine administered parenterally (10) had been used. This vaccine exacerbated RSV disease and was withdrawn from use (10). A number of live attenuated forms of RSV have been proposed for treatment of RSV infection (87, 89). However, there are limitations imposed by such approaches. For example, live infection does not provide full immunity and single point mutations may revert to wild type with undesirable consequences.
A need exists for a better way to treat RSV. The present invention is directed to a new approach to achieve this objective.